Modified headpiece for hydraulic coil deployment system

ABSTRACT

A vascular occlusion device for use with a hydraulic deployment catheter is provided. The vascular occlusion device includes a headpiece that has a deformable interference element which changes from an initial configuration to a deformed configuration upon an increase of hydraulic pressure within the deployment catheter. When the interference element is in the initial configuration, the headpiece is secured to the deployment catheter, and when the interference element is in the deformed configuration, the headpiece can be removed from the deployment catheter for deployment of the occlusion device.

FIELD OF THE INVENTION

The present invention is related to the delivery of embolic occlusiondevices. Disclosed are occlusion devices having a modified headpiece foruse with hydraulic deployment systems and methods for deploying suchocclusion devices at a preselected location within a patient, in anaccurate and rapid manner. The occlusion devices and methods areparticularly well suited for deployment of the occlusion devices at alocation of concern within the vasculature, especially intracranially,of a patient.

BACKGROUND OF THE INVENTION

The use of catheter delivery systems for positioning and deployingtherapeutic devices, such as dilation balloons, stents and emboliccoils, in the vasculature of the human body has become a standardprocedure for treating endovascular diseases. It has been found thatsuch devices are particularly useful in treating areas where traditionaloperational procedures are impossible or pose a great risk to thepatient, for example in the treatment of aneurysms in intracranial bloodvessels. Due to the delicate tissue surrounding intracranial bloodvessels, especially for example brain tissue, it is very difficult andoften risky to perform surgical procedures to treat defects ofintracranial blood vessels. Advancements in catheter deployment systemshave provided an alternative treatment in such cases. Some of theadvantages of catheter delivery systems are that they provide methodsfor treating blood vessels by an approach that has been found to reducethe risk of trauma to the surrounding tissue, and they also allow fortreatment of blood vessels that in the past would have been consideredinoperable.

Typically, these procedures involve inserting the distal end of aguiding catheter into the vasculature of a patient and traversing itthrough the vasculature to a predetermined delivery site. A vascularocclusion device, such as an embolic coil, is attached to the distal endof a deployment catheter which pushes the occlusion device through theguiding catheter and out of the distal end of the guiding catheter intothe delivery site. Some of the problems that have been associated withthese procedures relate to the accuracy of occlusion device placement.For example, once the occlusion device is pushed out of the distal endof the guiding catheter, the occlusion device cannot be retracted andmay migrate to an undesired location. Often, retrieving andrepositioning the occlusion devices requires a separate procedure andhas the potential to expose the patient to additional risk.

In response to the above mentioned concerns, numerous devices andrelease mechanisms have been developed in an attempt to create deliverysystems which provide both control of an occlusion device after thedevice has exited the guiding catheter and a rapid release or detachmentmechanism to release the device from the deployment catheter once theocclusion device is in place.

One such device is disclosed in Lulo et al. U.S. Pat. No. 6,544,225,currently assigned to the same assignee as the subject application andhereby incorporated herein by reference. Lulo et al. discloses ahydraulic deployment system that has a deployment catheter having alumen extending throughout the length of the catheter. The catheter hasa distal end portion that is formed from a material which expandsoutwardly when a liquid is applied within the lumen of the catheter. Aproximal end portion of an occlusion device is disposed in fluid-tightengagement within the lumen of the distal portion of the catheter. Theproximal end portion of the occlusion device is typically a generallycylindrical section that, prior to assembly of the system, has a greaterdiameter than the distal end portion of the deployment catheter prior toassembly of the system and prior to expansion. A frictional engagementis formed by inserting the larger diameter proximal end portion of theocclusion device into the smaller diameter distal end portion of thedeployment catheter. The objective of this prior system is to providefrictional engagement to not only form a fluid-tight seal but also tosecure the occlusion device to the deployment catheter until the desireddeployment of the occlusion device. When fluid is applied within thelumen of the deployment catheter, the distal end portion of thedeployment catheter expands outwardly and the proximal end portion ofthe occlusion device is release, thereby deploying the occlusion device.

There remains a need for a coupling assembly that provides a highstrength attachment between the occlusion device and the deploymentcatheter during the advancement of the occlusion device through thevasculature of a patient, and also allows for a rapid release of theocclusion device at the desired time of deployment, without having torely upon tight sizing relationships between tubular members and tubularexpansion.

SUMMARY OF INVENTION

The present invention embodies occlusion devices for use with hydraulicdeployment systems. The occlusion devices include a headpiece that canbe inserted into a distal end portion of a lumen of a hydraulicdeployment system deployment catheter. A deformable interferenceelement, which has an initial configuration and a deformedconfiguration, is located at the proximal end portion of the headpiece.In the initial configuration, the interference element engages a sectionof the distal end portion of the deployment catheter to secure theheadpiece within the lumen and to provide a high strength attachmentbetween the occlusion device and the deployment catheter. Whensufficient fluid pressure is applied to the interference element, thepressure causes the interference element to transition into the deformedconfiguration. In the deformed configuration, the engagement between theinterference element and the distal end portion of the deploymentcatheter lessens, or the interference element completely disengages fromthe distal end portion of the deployment catheter, and the headpiece isallowed to be advanced out of the lumen of the deployment catheter.

In one preferred embodiment, the distal end of the deployment catheteris comprised of a substantially rigid sleeve, such as a metal hypotube.The proximal end portion of the sleeve includes a ridge or lip thatprovides an interference surface. An occlusion device having acylindrical headpiece is inserted into the sleeve. The proximal endportion of the headpiece has an interference element in the form of aradial flare that extends radially from the proximal end portion of theheadpiece. The radial flare has a diameter larger than that of theproximal end portion of the sleeve and engages the lip at the proximalend portion of the sleeve to secure the headpiece within the sleeve.

When it is desired to deploy the occlusion device, fluid is introducedinto the lumen of the deployment catheter to apply fluid pressure to theinterference element. The fluid pressure causes the radial flare toslightly fold or deform so the flare is allowed to be pushed distallypast the lip of the sleeve and the headpiece is allowed to be pushed outof the distal end of the sleeve.

Other aspects, objects and advantages of the present invention will beunderstood from the following description according to the preferredembodiments of the present invention, specifically including stated andunstated combinations of the various features which are describedherein, relevant information concerning which is shown in theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In describing the preferred embodiments of the present invention,reference will be made to the accompanying drawings, wherein:

FIG. 1 is an enlarged partially sectioned view of an occlusion devicedeployment system in accordance with a preferred embodiment of thepresent invention;

FIG. 2 is an enlarged partially sectioned view of the occlusion devicedeployment system shown in FIG. 1, during release of the occlusiondevice;

FIG. 3 is a perspective view of one embodiment of a coupling element inaccordance with the present invention, shown prior to deformation of theinterference element;

FIG. 4 is a perspective view of the coupling element of FIG. 3, shownafter the interference element has been deformed;

FIG. 5 is a cross-sectional view of the coupling element shown in FIG.3, taken along lines 5-5; and

FIG. 6 is a cross-sectional view of the coupling element shown in FIG.4, taken along lines 6-6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention, which may be embodied in variousforms. Therefore, specific details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one skilled in the art to variouslyemploy the present invention in virtually any appropriate manner.

FIGS. 1 and 2 generally illustrate a preferred embodiment of thehydraulic occlusion device deployment system and occlusion device of thepresent invention. The deployment system, generally designated at 10,includes an elongated deployment catheter 12 that can be inserted andadvanced through a guide catheter (not shown) to guide an occlusiondevice 11 to a preselected site within the vascular 14 of a patient in amanner generally known in the art.

The illustrated deployment catheter 12 is comprised of a series ofribbon coils 16 enclosed within a polymer sheath 18. It will beunderstood that the deployment catheter can be any type of deploymentcatheter suitable for deployment of occlusion devices. The deploymentcatheter 12 includes a proximal end portion (not shown) and a distal endportion 20. A lumen 22 extends along the deployment catheter 12 from theproximal end portion to the distal end portion 20.

A hydraulic source (not shown) is operatively connected to the proximalend portion of the deployment catheter 12 to inject fluid into thedeployment catheter lumen 22 and to increase fluid pressure within saidlumen. The hydraulic source can be similar to the hydraulic syringesystem disclosed in U.S. Pat. No. 6,544,225 to Lulo, et al., assigned tothe same assignee of the present application and incorporated herein byreference. The hydraulic source could also be any other suitablehydraulic source known in the art. Typical hydraulic fluid is salinesolution or other material suitable for internal medical use.

A coupling sleeve 24 is located at the distal end portion 20 of thedeployment catheter 12. The coupling sleeve 24 has a tubularconfiguration that includes a lumen 26 (shown in FIG. 2) whichcommunicates with lumen 22. The coupling sleeve 24 is preferably made ofa rigid or semi-rigid material so that the configuration of the couplingsleeve does not substantially change, i.e., expand, upon an increase influid pressure within the lumen 26. Preferably, the coupling sleeve iscomprised of a metal hypotube. Alternatively, the coupling sleeve 24 canbe comprised of any other rigid or semi-rigid material that does notchange configuration in response to fluid pressure within a catheter,such as a high Durometer polymer.

The coupling sleeve 24 has an indented proximal end portion 28 that issized to fit into the lumen 22 at the distal end portion 20 ofdeployment catheter 12. The coupling sleeve 24 and the deploymentcatheter 12 are preferably separate components that are secured togetherby, for example, adhesive or solder. It is also contemplated that thecoupling sleeve 24 and the deployment catheter 12 could be a unitarystructure form by, for example, extrusion or molding.

The occlusion device 11 includes an embolic element 30 and a headpiece32 which are illustrated as separate components that are securedtogether by adhesive or solder; however, it will be understood that theembolic element 30 and the headpiece 32 can be of a unitary structurewhich forms the occlusion device.

The embolic element 30 is preferably an embolic coil which can be of thetype that takes a substantially linear configuration for being advancedthrough the guide catheter and a randomly oriented relaxed conditionafter it has exited from the guide catheter. Alternatively, the embolicelement 30 may be any other type of embolic element which may take onvarious forms and configurations, such as hydrogels, foams, bioactivecoils, braids, cables and hybrid devices.

The occlusion device headpiece 32 has distal end portion 34 and anindented proximal end portion 36. The distal end portion 34 is connectedto the embolic element 30, and the proximal end portion 36 is sized tofit within the lumen 26 of the coupling sleeve 24.

A coupling element 38 is located at the proximal end portion 36 of theheadpiece 32. In the illustrated embodiment, referring to FIGS. 5 and 6,the coupling element 38 is generally cylindrical and includes a proximalwall 40 and a circumferential sidewall 42 defining a cavity 44 withinthe coupling element. An opening 46 is located at the distal end 48 ofthe coupling element 38. The coupling element 38 is attached to theheadpiece 32 by placing the coupling element over the indented proximalend portion 36 of the headpiece so that the proximal end portion 36 ofthe headpiece enters the opening 46 and is located within the cavity 44of the coupling element, as shown in FIGS. 1 and 2. The coupling element38 and the headpiece 32 are then secured together, for example, byadhesives or solder. The proximal end portion 36 of the headpiece 32 isindented so that the circumferential sidewall 42 of the coupling element38 can fit between the headpiece 32 and the coupling sleeve 24. Whendesired, the size of the indent of the proximal end portion 36 of theheadpiece 32 is substantially equal to the thickness of thecircumferential sidewall 42 so that the outer surface of thecircumferential wall and outer surface of the headpiece generally align.

Referring to FIGS. 3, 4, 5 and 6, the proximal wall 40 of the couplingelement 38 includes a deformable interference element 50.Illustratively, the deformable interference element 50 is comprised of aradially flared proximal tip 52 of the coupling element. The deformableinterference element 50 includes an initial configuration, asillustrated in FIGS. 3 and 5, and a slightly deformed or foldedconfiguration, as illustrated in FIGS. 4 and 6. Preferably, theinterference element 50 is made from a deformable material that willdeform when a hydraulic pressure between about 100 psi and about 1000psi, typically between about 200 psi and about 900 psi, is applied tothe interference element. Such materials include flexible metals, metalalloys, such as Nitinol, and deformable polymers.

Referring to FIGS. 3 and 5, in the initial configuration, the flaredproximal tip 52 is flared radially and the outer surface 54 of theproximal wall 40 is flat. When the headpiece 32 is placed within thecoupling sleeve 24 prior to deployment, the radial flared proximal tip52 engages an interference surface located on the deployment catheter.In the illustrated embodiment, the radial flared proximal tip 52 has alarger diameter then a lip 56 located at the proximal end of thecoupling sleeve 24, and the radial flared proximal tip 52 engages withthe lip 56 to provide a high strength attachment between the headpiece32 and the coupling sleeve 24, as illustrated and FIG. 1.

Referring to FIG. 2, when fluid 58 enters the lumen 22 and hydraulicpressure is applied to the coupling element 38, the interference element50 transitions into a deformed configuration. In the deformedconfiguration, the flared proximal tip 52 is slighted folded or deformedinwardly. In the illustrated embodiments, the surface 54 of the proximalwall 40 of the coupling element 38 is thereby curved in a concaveddish-like shape, as illustrated in FIGS. 2, 4 and 6. The deformedconfiguration allows the flared proximal tip 52 of the coupling member38 to be advanced distally past the lip 56 of the coupling sleeve 24,and the headpiece 32 is pushed out to the lumen 26 of coupling sleeve 24under the force of the hydraulic pressure.

In use, with the flared proximal tip 52 of the coupling member 38 in theinitial configuration and engaging lip 56 of the coupling sleeve 24, theheadpiece 32 of the occlusion device 11 is disposed within the lumen 26of the coupling sleeve 24 to securely attach the occlusion device 11 tothe deployment catheter 12, as illustrate in FIG. 1.

A guide catheter can be inserted into the vasculature system of apatient, and the distal end portion of the guide catheter can bepositioned at a preselected location within a blood vessel, typically inconjunction with other devices and professional procedures as generallyknown in the art. The deployment catheter 12 having an occlusion device11 is inserted into a proximal end portion of the guide catheter, andthe deployment catheter 12 is advanced through the guide catheter untilthe occlusion device 11 reaches the distal end portion of the guidecatheter.

Once the occlusion device 11 reaches the distal end portion of the guidecatheter, the occlusion device 11 may be moved out of the distal endportion of the guide catheter by moving the guide catheter in aretrograde manner, by advancing the deployment catheter 12, or by acombination of moving the guide catheter in a retrograde manner andadvancing the deployment catheter.

The occlusion device 11 can include at least one radiopaque marker,preferably located in the headpiece 32, so that the position of theocclusion device 11 can be monitored by fluoroscopy. After the occlusiondevice 11 has exited the guide catheter, if it is determined that theocclusion device is in the wrong position and/or a different occlusiondevice is required, the deployment catheter 12 can be retracted to movethe occlusion device back into the guide catheter. Once in the guidecatheter, the occlusion device 11 can be repositioned or completelyremoved from the patient.

After it has been determined that the occlusion device 11 is at thedesired location within the patient, the hydraulic source is activatedto inject fluid 58 into the lumen 22 of the deployment catheter 12 andto increase the fluid pressure within the lumen 22. The increased fluidpressure is applied to the coupling element 38 which causes theinterference element 50 to deform, e.g., the flared proximal tip 52slightly folds or deforms inward, as illustrated in FIG. 2. With theinterference element 50 deformed, hydraulic pressure advances theinterference element 50 past the lip 56 of the coupling sleeve 24, andthe headpiece 32 is pushed out of the coupling sleeve 24, therebydeploying the occlusion device.

It will be understood that the embodiments of the present inventionwhich have been described are illustrative of some of the applicationsof the principles of the present invention. Numerous modifications maybe made by those skilled in the art without departing from the truespirit and scope of the invention, including those combinations offeatures that are individually disclosed or claimed herein.

1. An occlusion device deployment system, comprising: a deploymentcatheter having a proximal end portion, a distal end portion, a lumentherethrough, a distal edge, and an interference surface along thedistal end portion and spaced proximally from the distal edge, theinterference surface being a radially extending lip within the distalend portion of the deployment catheter; a hydraulic pressure locatedwithin the lumen of the deployment catheter; an occlusion device havinga proximal end portion, said proximal end portion of the occlusiondevice removably disposed within the lumen of the deployment catheter; adeformable interference element located on the proximal end portion ofthe occlusion device, the interference element comprises a deformableradially extending flare extending from the proximal end portion of theocclusion device, said deformable interference element having an initialconfiguration in which the flare extends radially outwardly and adeformed configuration in which the flare is deformed radially inwardlyand longitudinally from the initial configuration, and the interferenceelement transitions from the initial configuration to the deformedconfiguration upon an increase in the hydraulic pressure within thelumen of the deployment catheter; wherein the deformable radial flareinterference element engages the radially extending lip interferencesurface within the deployment catheter to secure the proximal endportion of the occlusion device in the lumen of the deployment catheterwhen the deformable interference element is in the initialconfiguration; and wherein the deformable radial flare interferenceelement disengages the radially extending lip interference surfacewithin the deployment catheter when the radial flare interferenceelement is in the deformed configuration, allowing the proximal endportion of the occlusion device to be removed from the lumen of thedeployment catheter.
 2. The deployment system of claim 1 in which theproximal end portion of the occlusion device comprises an occlusiondevice headpiece.
 3. The deployment system of claim 1 in which theproximal end portion of the occlusion device is cylindrical.
 4. Thedeployment system of claim 1 in which the interference element iscomprised of a flexible polymer.
 5. The deployment system of claim 1 inwhich said transition takes place when the hydraulic pressure within thelumen of the deployment catheter is 100 psi or greater.
 6. Thedeployment system of claim 1 in which the occlusion device includes anembolic coil.
 7. The deployment system of claim 1 in which the distalend portion of the deployment catheter is comprised of a coupling sleeveand the interference surface is a portion of the coupling sleeve.
 8. Thedeployment system of claim 7 in which the coupling sleeve is made from amaterial that does not change configuration upon an increase ofhydraulic pressure within the lumen of the deployment catheter.
 9. Thedeployment system of claim 8 in which the coupling sleeve is comprisedof a metal hypotube secured to the distal end portion of the deploymentcatheter.